                Harris I, “Gradual closure of fasciotomy wounds using a vessel loop shoelace”, Injury 1993; 24(8): 565-6,        Asgari M M, Spinelli H M, “The vessel loop shoelace technique for closure of fasciotomy wounds”, Ann Plast Surg 1999; 43: 225-9,        Bashir A H, “Wound closure by skin traction: an application of tissue expansion”, Br J Plast Surg 1987; 40(6): 582-7,        Bulstrode C J, “A simple method for closing fasciotomies”, Ann R Col Surg Engl 1985; 67(2): 119-20,        Almekinders L C, “Gradual closure of fasciotomy”, Orthop Rev 1991; 20(1): 82-4,        Monnier J, “Extension tissulaire uni-axiale dans la couverture des pertes de substance des membres” (Uniaxial tissular extension in the coverage of limb substance loss), Annal chir plast 52 (2007): 577-581.        
This technique uses elastic properties of the skin in particular, and consists in applying progressive tension on two edges of the skin around the wound when a direct suture is impossible due to loss of substance, excessive tension between the two skin edges or during discharge aponevrotomies made in the case of a compartment syndrome. A compartment syndrome is defined as a neuromuscular complaint that can lead to necrosis, related to an increase in the intratissular pressure in an inextensible muscular compartment. It is secondary to trauma or ischemia. The only way of reducing the pressure in the compartment is to open it widely. This action is done is vascular surgery or orthopaedic surgery and can save the muscle concerned and its function, but it causes a large skin gap equivalent to a loss of substance.
Therefore the invention is applicable to the treatment of a long wound with a surface area of between 100 cm2 and 500 cm2 and for example resulting from a aponevrotomy operation or ablation of a skin tumour. The invention is also applicable to the treatment of a smaller wound, for example with an area of less than 100 cm2, for example resulting from a post-operational disunion.
The principle of external tissular extension is to apply progressive traction on the two skin edges to bring them together and ideally to bring them into contact such that the wound is completely closed. The skin expansion system is put into place at the end of the operation. The progressive traction is generally applied immediately after the operation (second day after the operation) and is continued for about fifteen days. Traction is increased at the patient's bed every forty-eight hours. The skin expansion system is removed without anaesthetic.
At the present time, this technique is applied using standard equipment not used in the way it was intended, and particularly by:                a silicone loop as an elastically deformable tie intended to extend between the tissues surrounding the wound such that a tension in the tie creates traction along the tissues surrounding the wound to bring said tissues towards each other, the silicon loop is then not used as it was intended which is per-operational marking of vascular or noble structures (ureter, bile duct),        staples usually used for closing the skin at the end of an operation,        a tensioner adapted to maintain tension in the tie.        
The tie in this known skin expansion system passes in sequence through the staples, anchored through the tissues surrounding the wound. The tie is then held in tension by the tensioner, for example in the form of a cleat on one or several staples.
However, although very widespread and ethical because it is used in a rescue situation in which there is no alternative solution, the skin extension technique making use of medical equipment designed for other purposes often has disappointing results.
In particular, the known skin expansion system is long and complex to implement due to the need to start by anchoring staples along the tissues surrounding the wound. Furthermore, in this known skin expansion system, traction on the tissues surrounding the wound is applied through staples and depends on the anchorage of each staple. Despite the care taken in anchoring staples, they do not allow controlled traction, particularly along an appropriate direction. Therefore the known skin expansion system cannot apply uniform traction along the tissues surrounding the wound. There is then a risk of damage or even necrosis of the tissues, at least locally and particular at the locations at which tension is highest. Furthermore, staples diverted from their normal use do not have any particular mechanical properties and there is a risk of them tearing out.
Other examples of a skin expansion system according to the preamble of claim 1 are described in documents US 2012/0016384 and US 2003/0092969. However, due to the envisaged anchors, these skin expansion systems create a serious risk of damaging or even tearing tissues surrounding the wound.
The invention aims to mitigate the problems mentioned above.